A capitulary (medieval Latin capitularium) was a series of legislative or administrative acts emanating from the Frankish court of the Merovingian and Carolingian dynasties, especially that of the first emperor of the Romans in the west since the deposition of Romulus Augustulus, Charlemagne. They were so called because they were formally divided into sections called capitula (plural of capitulum, a diminutive of caput meaning "head(ing)", i.e. chapters).
As soon as the capitulary was composed, it was sent to the various functionaries of the Frankish empire, archbishops, bishops, missi dominici and counts, a copy being kept by the chancellor in the archives of the palace. The last emperor to compose capitularies was Lambert in 898.
At the present day we do not possess a single capitulary in its original form; but very frequently copies of these isolated capitularies were included in various scattered manuscripts, among pieces of a very different nature, ecclesiastical or secular. We find, therefore, a fair number of them in books which go back as far as the 9th or 10th centuries. In recent editions in the case of each capitulary it is carefully indicated from what manuscripts it has been collated.
These capitularies make provisions of a most varied nature; it was therefore found necessary at quite an early date to classify them into chapters according to the subject. In 827 Ansegisus, abbot of St. Wandrille at Fontenelle, made such a collection. He embodied them in four books: one of the ecclesiastical capitularies of Charlemagne, one of the ecclesiastical capitularies of Louis I (Charlemagne's son), one of the secular capitularies of Charlemagne, and one of the secular capitularies of Louis, bringing together similar provisions and suppressing duplicates. This collection soon gained an official authority, and after 829 Louis the Pious refers to it, citing book and section. See also Capitularies of Charles the Bald.